Remove unused property
Remove unused property

The property `external_host` was removed from cf-mysql release in v35 - https://github.com/cloudfoundry/cf-mysql-release/releases/tag/v35

The MySQL team recommends using this ops file if you require a route for the proxy - https://github.com/cloudfoundry/cf-mysql-deployment/blob/develop/operations/register-proxy-route.yml
emalm/cf-deployment,cloudfoundry/cf-deployment,cloudfoundry/cf-deployment